Effects of Decreased Vitamin D and Accumulated Uremic Toxin on Human CYP3A4 Activity in Patients with End-Stage Renal Disease

In patients with end-stage renal disease, not only renal clearance but also hepatic clearance is known to be impaired. For instance, the concentration of erythromycin, a substrate of cytochrome P450 3A4 (CYP3A4), has been reported to be elevated in patients with end-stage renal disease. The purpose of this study is to elucidate the reason for the decrease in hepatic clearance in patients with end-stage renal disease. Deproteinized pooled sera were used to assess the effects of low-molecular-weight uremic toxins on CYP3A4 activity in human liver microsomes and human LS180 cells. Four uremic toxins (3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, hippuric acid, indole-3-acetic acid, and 3-indoxyl sulfate) present at high concentrations in uremic serum were also studied. Simultaneous treatment of uremic serum (less than 10%) or uremic toxins did not affect testosterone 6β-hydroxylation in human liver microsomes. On the other hand, pretreatment of each serum activates CYP3A4 in LS180 cells, and the increased CYP3A4 activity in uremic serum-treated cells was smaller than normal serum-treated cells. In addition, CYP3A4 and CYP24A1 mRNA levels also increased in LS180 cells exposed to normal serum, and this effect was reduced in uremic serum-treated cells and in cells exposed to uremic serum added to normal serum. Furthermore, addition of 1,25-dihydroxyvitamin D to uremic serum partially restored the serum effect on CYP3A4 expression. The present study suggests that the decrease of 1,25-dihydroxyvitamin D and the accumulation of uremic toxins contributed to the decreased hepatic clearance of CYP3A4 substrates in patients with end-stage renal disease.     

Deficiency of Myo18B in mice results in embryonic lethality with cardiac myofibrillar aberrations

Myo18B is an unconventional myosin family protein expressed predominantly in muscle cells. Although conventional myosins are known to be localized on the A-bands and function as a molecular motor for muscle contraction, Myo18B protein was localized on the Z-lines of myofibrils in striated muscles. Like Myo18A, another 18th class of myosin, the N-terminal unique domain of the protein and not the motor domain and the coiled-coil tail is critical for its localization to F-actin in myocytes. Myo18B expression was induced by myogenic differentiation through the binding of myocyte-specific enhancer factor-2 to its promoter. Deficiency of Myo18B caused an embryonic lethality in mice accompanied by disruption of myofibrillar structures in cardiac myocytes at embryonic day 10.5. Thus, Myo18B is a unique unconventional myosin that is predominantly expressed in myocytes and whose expression is essential for the development and/or maintenance of myofibrillar structure.     

A study of the usefulness of pancreatic juice cytology obtained via an endoscopic nasal pancreatic drainage (ENPD) tube

We studied the usefulness of pancreatic juice cytology obtained via an indwelling endoscopic nasal pancreatic drainage (ENPD) tube. In general, cytology was performed three times. The sensitivity was 0.35 on the first time and 0.59 after three times (p<0.01). The sensitivity in relation to tumor size of pancreatic cancer was 0.77 for Tis (3 cases) and TS1 (10 cases), 0.76 for TS2 (29 cases), 0.56 for TS3 (9 cases) and 0 for TS4 (4 cases). A significant difference of p=0.01 was recognized among the 4 groups, and the sensitivity for small tumors was higher than that for large tumors. The pancreatic juice can be obtained repeatedly via the ENPD tube and that contributes to improving the diagnostic accuracy. It is useful as a definitive diagnosis method in early stage pancreatic cancer because it is easier to detect positive results in smaller tumor, furthermore, it is possible to diagnose carcinoma in situ.     

First Case Report of Fatal Sepsis Due to Campylobacter upsaliensis

We encountered a rare case of severe fatal infection in a 70-year-old woman due to Campylobacter upsaliensis, identified by PCR amplification and sequencing analysis of the 16S rRNA gene using DNA extracted from the isolates. To our knowledge, fatal sepsis due to this organism has never been described to date.     

Primary cutaneous anaplastic large cell lymphoma occurring in an atopic dermatitis patient: a case report with review of the literature with emphasis on their association

Although the risk of malignant lymphoma in patients with atopic dermatitis (AD) remains controversial, an increased risk of malignant T-cell lymphoma in patients with AD has been reported. Primary cutaneous anaplastic large cell lymphoma (C-ALCL) is a relatively common distinct clinicopathological entity. However, occurrence of C-ALCL in patients with AD has been rarely reported. Herein, we describe the 5^th reported case of C-ALCL occurring in a patient with AD and review the clinicopathological features. A 30-year-old Japanese male with a long-standing history of AD presented with a gradually enlarged nodular lesion in the right abdominal wall, which had spontaneously regressed without therapy. Two years later, multiple nodular lesions appeared in his trunk, and swelling of multiple lymph nodes was also detected. Histopathological studies demonstrated diffuse proliferation of large-sized lymphocytes with large convoluted nuclei containing conspicuous nucleoli and relatively rich cytoplasm in the skin and lymph node. Immunohistochemically, these lymphocytes were positive for CD30, CD8, and MUM1, and negative for CD3, CD4, and ALK1. Accordingly, a diagnosis of primary C-ALCL was made. The patient died of disease after various courses of chemotherapy. Our clinicopathological review revealed that the prognosis of C-ALCL occurring in patients with AD is poor because two of 5 patients died of disease. Therefore, albeit extremely rare, AD patients with C-ALCL should be monitored closely, and additional clinicopathological studies are needed to clarify the pathogenesis of C-ALCL occurring in patients with AD.